The present disclosure relates to person support apparatuses, such as beds, cots, stretchers, operating tables, recliners, or the like. More specifically, the present disclosure relates to person support apparatuses that include sensors for detecting when an occupant of the person support apparatus has exited therefrom, or may be about to exit therefrom.
Existing hospital beds and/or stretchers often include a bed exit system that is adapted to detect when a patient has exited the bed, or when a patient may be about to exit the bed. Typically, such beds include circuitry for providing an audio or visual alert when such an exit or pre-exit situation is detected. In many cases, the bed or stretchers include circuitry for transmitting a signal to a remote location, such as a nurses' station, so that the appropriate caregivers are notified of the exit, or pre-exit condition, and can respond appropriately. Existing exit detection systems often rely on an analysis of the outputs of multiple load cells. In some existing systems, the load cells outputs are monitored to compute a location of the occupant and if that location moves out of a defined area, an exit alert is issued. In other existing systems, the load cell outputs are monitored and one or more ratios of the forces detected by one or more of the load cells are computed. If the one or more ratios change by an amount greater than a threshold amount, an exit alert is issued.